Rasheed Sabreen Sabah, Jawad Hussien Ali
Institute of Laser for Postgraduate Studies, University of Baghdad, Baghdad, Iraq.
Iran Endod J. 2021 Fall;16(4):238-243. doi: 10.22037/iej.v16i4.34544.
The purpose was to study the influence of Erbium,Chromium:Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser at short pulse duration on smear layer removal from apical root third.
Twenty-four single-rooted mandibular premolars were used. The roots length was cut to 14 mm and instrumented using the Protaper Gold system to size 40/0.06. The samples were divided into four groups (=6) as follows: (A) conventional irrigation with 5 mL of 17% Ethylenediaminetetraacetic acid ( EDTA), (B) passive ultrasonic irrigation with 5mL of 17% EDTA, (C) Er,Cr:YSGG induced photoacoustic streaming (PIPS) with 5 mL of 17% EDTA and (D)Er,Cr: YSGG induced PIPS with 5 mL of 5.25% sodium hypochlorite (NaOCl). After final irrigation with normal saline and drying, the roots were painted with nail varnish externally, and 2%methylene blue dye was injected into the canal. The tooth split horizontally at the fourth millimetres. The picture was taken by a professional Digital SLR camera. The dye penetration was measured using analytical software (measure picture CAD-KAS Kessler Germany). Dunnett's test was used to compare control group against experimental groups.
After the statistical test, the highest mean percentage was presented in the laser group with 17% EDTA (Group C=85.9804) followed by the laser group with 5.25% NaOCl (Group D=69.7817) and ultrasonic group (Group B=34.5453) respectively and the lowest mean percentage was in the control group (Group A=20.7969).
Based on this in vitro study, PIPS technique using Er,Cr:YSGG pulse laser (0.5 W,5 Hz, air and water off) at short pulse duration and 17% EDTA proved effectively in smear layer removal, while the PIPS proved an acceptable result when the laser is used alone assisted by NaOCl.
本研究旨在探讨短脉冲持续时间的铒铬钇钪镓石榴石（Er,Cr:YSGG）激光对根尖三分之一处玷污层去除的影响。
使用24颗单根下颌前磨牙。将牙根长度截短至14mm，并用Protaper Gold系统预备至40/0.06规格。样本分为四组（每组6颗），如下：（A）用5mL 17%乙二胺四乙酸（EDTA）进行常规冲洗；（B）用5mL 17% EDTA进行被动超声冲洗；（C）用5mL 17% EDTA进行Er,Cr:YSGG诱导的光声流（PIPS）；（D）用5mL 5.25%次氯酸钠（NaOCl）进行Er,Cr:YSGG诱导的PIPS。用生理盐水最终冲洗并干燥后，牙根外部涂指甲油，向根管内注入2%亚甲蓝染料。在4mm处水平劈开牙齿。用专业数码单反相机拍照。使用分析软件（德国CAD-KAS Kessler测量图片）测量染料渗透情况。采用Dunnett检验将对照组与实验组进行比较。
经统计学检验，激光联合17% EDTA组（C组=85.9804）平均百分比最高，其次是激光联合5.25% NaOCl组（D组=69.7817）和超声组（B组=34.5453），平均百分比最低的是对照组（A组=20.7969）。
基于本体外研究，短脉冲持续时间（0.5W，5Hz，关闭空气和水）的Er,Cr:YSGG脉冲激光联合17% EDTA的PIPS技术在去除玷污层方面效果显著，而单独使用激光并辅以NaOCl时，PIPS也取得了可接受的结果。
